The Research Of LTE Physical Downlink Control Channel Based On FPGA

With the rapid development of science and technology, mobile communicationtechnology has gradually matured. The mobile communications have occurred hugechanges from the first generation to LTE. It significantly increases the spectralefficiency and data transmission rate because of the used of some key transmissiontechnologies, like OFDM and MIMO. LTE system has two formats: FDD-LTE andTDD-LTE, namely LTE frequency division duplex LTE systems and time divisionduplex system. Today’s business operators are competing for the market share in LTE,LTE technology will occupy an important position in the future field ofcommunication.With the advances in integrated circuit technology, the development and production ofcommunication-related products have a broader platform, and FPGA graduallybecomes the main force in the field of integrated circuits. Compared with theconventional digital circuits, FPGA owns advantages in programmable, high-speed,high reliability and high level of integration, etc. The board-level circuit designperformed on the chip improving the circuit performance, reducing workload anddifficulty of the printed circuit board design, effectively improving the flexibility andefficiency of the design. And FPGA has the advantages on high clock frequencies, fastand flexible organizational internal delays, and it is widely used in communications,military and medical fields.This paper research the implementation of the LTE downlink control channel physicallayer algorithm based on FPGA, including circuit architecture built of sourcegeneration, adding redundancy check, coding, scrambling and modulation. Theachieving of simulation algorithms of various parts are on the platform of Altera’sFPGA development board, and use the Verilog HDL language and the internal IPcore to complete the FPGA logic circuit design. After inoputting the code andintegrating by QuartusII and Modelsim functional simulation, the comparison will bemade with the outputs of channel and modeling results of Matlab. And the consistentresults verify the baseband algorithms logic circuit of LTE downlink control channelphysical layer reaching agreement requirements.The paper only research the circuit design of physical layer downlink control channel.Of course, the entire physical layer signaling flow need other channels and theassociated physical uplink signals, which are critical to build the base station. Thesubsequent research direction of this paper is to improve the base station physicallayer circuit, including other parts of baseband, like RF, PCIE and timing controlsection. Eventually, forming the signaling communication with terminal emulationinstrument-TM500and development circuits-base station, it can verify theimplementation LTE protocol algorithm.